The present invention relates to baffles for use in sewage and water settling tanks and more particularly to a baffle arrangement which establishes a substantially uniform flow in any vertical plane parallel to the planes of the end walls of the tank. This permits a "wall of water" to proceed at a uniform velocity down the tank from the inlet end to the outlet end.
It is known that the settling rate is enhanced in any sewage or water settling tank by maintaining flow in the tank uniform and non-turbulent, both at the surface of the tank and at the bottom and across the width of the tank. The liquid to be treated is usually introduced at one end of the tank through one or two inlet openings. This creates a great rush of liquid at the inlet end and the liquid must move down the tank some distance before the desired uniform flow is established. One way of breaking up this rush of liquid at the inlet and is simply to place a baffle plate immediately in front of each inlet opening so that the stream of liquid on striking the plate is deflected both upwardly and downwardly by the plate. This has the effect of producing a vertical flow along the inlet end wall of the tank which is not desired. Further, the stream after striking the baffle plate as described still must flow some linear distance from the end wall before the liquids assume a smooth, uniform, non-turbulent flow. Increasing the number of baffles to provide the incoming liquid with a more tortuous flow path or increasing the number of inlet openings are other ways used to rapidly transform the stream of incoming liquid to a smooth, uniform, flow in the tank.
The present invention provides a simple, single baffle arrangement which quickly dissipates the energy of the stream of untreated liquid discharged to the tank so that a smooth, non-turbulent, uniform flow is quickly established. The construction of the baffle is such that it can be readily made from any light weight material such as fiberglass and installed into any existing settling tank. The structure of the baffle also is such that it can be formed integral with a scum trough so that the scum trough and the baffle can be incorporated into the settling tank as a single unitary structure.